Please help. Thank you!

David must install fencing around a lot that is shaped like a right angle. the side of lot that runs east-west is 200 ft long. the side of the lot runs north-south is 125 ft long. calculate how many feet of fencing he will need to surround the entire lot.

Multiply. write your answer in simplest form. 3/8 x 5/7

Complete the solution of the equation. find the value of y when x equals to 6 4x+y=20